1. Field of the Invention
Apparatuses consistent with the present invention relate to a projection type image display device, and more particularly, to an ultra-slim projection type image display device with a reduced height between the bottom of a screen and the bottom of a cabinet.
2. Description of the Related Art
Projection type image display devices are devices in which a display element selectively transmits light emitted from a light source to form a color image. The color image is enlarged and projected onto a screen.
Recently, brown tubes, which have a limited screen size despite being large systems, have been replaced with display devices capable of realizing a large screen size with a small thickness. Currently, projection type display devices make up a large portion of these display devices. Projection type image display devices have a slim profile and small-sized components while realizing a large screen such that the display devices can occupy a small area while realizing a large screen, and still provide high image quality.
To realize a projection type image display device with a large screen and a slim profile, a projection optical system should generate a bundle of light rays at a wide divergence angle. However, when the projection optical system is disposed at the central portion of a screen, the angle at which a bundle of light rays from the projection optical system are incident on the screen is limited. Referring to FIG. 1, to make a cabinet 50 of an image display device slimmer, a projection optical system 20 is disposed below a screen 40 and disposed at an oblique angle to the screen. When the projection type image display device operates, an image formed by a display element 10 is enlarged and projected through the projection optical system 20 to a reflection mirror 30, which reflects the image onto the screen 40. As a result, an image that corresponds to the oblique cross-section of a light bundle projected to the screen is formed on the screen 40, so that larger screen may be realized.
However, when the projection optical system 20 is located below the screen 40, a height h of the portion (referred to as ‘chin’ hereinafter) between the bottom of the cabinet 50 and the bottom of the screen 40 increases.